Sound-producing device.



E. C. BAYER.

SOUND PRODUCING DEVI APPLICATION FILED MAR. 27. 1

' Patented June 5, 1917 ERIK CHRISTIAN BAYER, OF JORDLtZlSE, SVEBLLESTATION, DENMARK.

SOUND-PRODUCING DEVICE.

Specification of Letters Patent. Patented June 5, 1917.

Application filed March 27, 1914.. Serial No. 827,652.

currents, produced by a telephone-transmit ter, into acousticvibrations. This is attained by a series of tightened wires ofnonmagnetic material being inserted in the circuit of thetelephone-transmitter, their individual rates of vibration beingadjusted so as to agree with the various tones corresponding to thenumber of periods of the alternating current, and the wires crossing apowerful magnetic field, sothatany alternating current, depending on itsperiodicity, will cause one of the wires to vibrateand thus produce thecorresponding tone.

On the drawing, Figures 1 and 2 represent one manner of constructing thedevice, in vertical and horizontal section, respectively.

Referring to the drawing, 1 is the iron frame of a bell-shapedelectromagnet with exciting coil 2 and an annular air slot 3. Throughthe latter a series of wires 4 is strung, their rate of vibration beingadjusted for instance at intervals of half a tone from wire to wire s0that, practically, all

audible tones are represented. The wlresare inserted in the circuit inthe telephone line, whose currents are to'be transformed, and may beconnected in series, in parallel or according to some combined system.

When now a powerful magnetic field is produced in the air slot by meansof constant current through the coil 2, then each of the alternatingcurrents, constituting the telephone-current, will cause the wire,correspondmgto the periodicity of the current,

- to vibrate-and only this wire-whereby the wire produces thecorresponding tone and, by the common action of all the wires, theentire telephone-current becomes converted into the corresponding tones,the voice, the song,.the music, etc. By making the magnetic field 3 verystrong, an extremely high intensification of the sound may be attained,and when, as represented in Fig. 1, a resonator 5, a sound-collector 6and a funnel 7 are provided, the device may be used as a loudly speakingtelephone.

The tones produced may also be caused to.

act on a microphone 8, whereby the tones are transformed intoalternating currents once more, the amplitude being increased, however.The device acts, in this case, as a telephone-relay and, in thisrespect,it p0$esses considerable advantages above the devices heretoforeknown. By the latter, the various tones are increased uniformly, but asthe various tones are variously weakened in the cable lines, nointelligible conversation will be attained by intensifying a greatlyweakened telephone current in an ordinary telephone relay.

By the above described device, however, it is practicable to intensifythe various tones to various extents, according to a definite plan, andthis may be effected by giving themagnetic field various strengthsopposite the various wires. effected by giving the air-slot 3 a varyingwidth at the various places. The magnets may-also be fitted withadjustable pole-pieces by which means the width of the air-slot may beregulated. In order to concentrate the field around the wires suitablemeans, preferably iron screws 9 (Fig. 1) maybe attached to thepole-piece.

By the means specified, it becomes practicable tointensify especiallythose tones which are mostly weakened in the cable lines, and,consequently, a device is attained differing from the heretofore knowntelephone-relays by not only intensifying the conversation but at thesame time making it more intelligible.

In Fig. 1, the microphone 8 is shown to be placed on the common support10 for the wires 4. The sound-waves, however, may also be transferred tothe microphone by way of the air, some fluid, or in any other knownmanner.

When the wires are placed in the fields of several magnets, theintensity of the various tones may be adjusted by variation of theintensity of the exciting current for the various magnets.

Several of the devices specified may be inserted in one telephone-line,and they may either be concentrated at one single place or In Fig. 2this is shown to be Having now particularly described and ascertainedthe nature of my said invention magnet producinga field passed throughby ability to emit ,amin out) n1 impure secondary sounds, for instancewhen'gramophone plates are used, the scratching of the pin on the plateand the foreign sounds pro duced by the diaphragm, so that th e voice,

the music, the song, etc, will appear with their orlginal timbre andharmony.

and in what manner the same is to be performed, I declare that what Iclaim is :o

1. In a sound reproducing device, the combination with a telephonetransmitter and its circuit, of a plurality of tightened wiresof-non-magnetic material adjusted to various tones and all constantlyforming inte gral'parts' of said circuit, and a' powerful I the saidwires.

' 2.. In a sound reproducing device, the com- -bination with a telephonetransmitter and its .circuit, of a pluralityof tightened wires r ofnon-magnetic material arranged in a cir-' 01c and adjustedto varioustones and all constantly forming integral parts, of said circuit, and, apowerful magnet producing r an annular. field passed through by the said7 wires. 4 V v 3. In a sound reproducing device, the combination with atelephone transmitter and its circuit, of a plurality of tightened wiresof non-magnetic material arranged in a cir-- cle and-adjustedto varioustones and all constantly formingv integral parts of said circuit, and apowerful magnet producing an annular field passed through by the saidwires and provided-with means for adjusting its field intensity inrespect of each in-.

dividual wire. 7

4:- In a sound reproducing-device, the combination with a telephonetransmitter and its circuit, of a plurality of tightened wires ofnon-magnetic material arranged in a circonvey said undulating electriccurrents, and

a powerful magnet producing a field passed through by the said wires.

The foregoing specification signed at C0- penhagen this 16th day ofMarch, 1914.

ERIK CHRISTIAN BAYER In presence of CARL Fox Man-m, I JULIUS IJEHMANN.

de and adjusted to various tones and all constantly forming integralparts of said

